P83C524 datasheet(21/76 Pages) PHILIPS

21 / 76 page

1997 Dec 15

Philips Semiconductors

Product speciﬁcation

8-bit microcontrollers

P83C524; P80C528; P83C528

9.3

Addressing

The P83C528 has five modes for addressing:

• Register

• Direct

• Register-Indirect

• Immediate

• Base-Register plus Index-Register-Indirect.

The first three methods can be used for addressing

destination operands. Most instructions have a

'destination/source' field that specifies the data type,

addressing methods and operands involved. For

operations other than MOVs, the destination operand is

also a source operand.

Access to memory addresses is as follows:

• Register in one of the four 8-bit register banks through

• 512 bytes of internal RAM through Direct or

RAM may be addressed directly/indirectly. Bytes

128-255 of internal RAM share their address location

with the SFRs and so may only be addressed indirectly

as data RAM. Bytes 0-255 of AUX-RAM can only be

addressed indirectly via MOVX.

• SFR through Direct addressing at address locations

128-255.

• External data memory through Register-Indirect

addressing.

• Program memory look-up tables through Base-Register

plus Index-Register-Indirect addressing.

P83C524 Datenblatt(PDF) 21 Page - NXP Semiconductors